Adjustable cam and adjusting means therefor

ABSTRACT

An adjustable cam formed of a single piece injection molded part in which a plurality of narrow strips are joined at common ends by yieldable loops and are disposed side-by-side; the adjacent strips being relatively movable longitudinally within the limits of the connecting loops and forming cam elements at their ends opposite from the loops which may be displaced to define collectively an adjustable cam surface. An embodiment of the adjustable cam includes a lateral extension on each strip forming opposed cam elements, and the cam is arranged in a circle. A cam adjusting means, including cam adjusting rollers, is rotatably mounted within the circle, and pivotal about a transverse axis so that by turning and pivoting the adjusting means, the cam strips are moved longitudinally to change the contour of the cam.

United States Patent Kane [151 3,654,817 [451 Apr.ll, 1972 3,l95,l ll3,391,868 3,433,091

ADJUSTABLE CAM AND ADJUSTING MEANS THEREFOR Neil G. Kane, HaciendaHeights, Calif. Rain Bird Sprinkler Mlg. Corp., Glendora, Calif.

lnventor:

Assignee:

Filed: May 6, 1970 Appl. No.: 35,091

References Cited UNITED STATES PATENTS 3,488,683 1/1970 Kerf00t,.lr.etal..74/568 Primary xaminerWilliam F. ODea Assistant Examiner-J. D.Shoemaker Attorney-Lyon & Lyon [57] ABSTRACT An adjustable cam formed ofa single piece injection molded part in which a plurality of narrowstrips are joined at common ends by yieldable loops and are disposedside-byside; the adjacent strips being relatively movable longitudinallywithin the limits of the connecting loops and forming cam elements attheir ends opposite from the loops which may be displaced to definecollectively an adjustable cam surface. An embodiment of the adjustablecam includes a lateral extension on each strip forming opposed camelements, and the cam is arranged in a circle. A cam adjusting means,including cam adjusting rollers, is rotatably mounted within the circle,and pivotal about a transverse axis so that by turning and pivoting theadjusting means, the cam strips are moved longitudinally to change thecontour of the cam.

7 Claims, 13 Drawing Figures PATENTEDAPHH m2 SHEU 1 OF 2 INVENTOR. A/E/LG/fA/vf ADJUSTABLE CAM AND ADJUSTING MEANS THEREFOR BACKGROUND OF THEINVENTION Cams are widely used to obtain predetermined motions. While itis often the case that it would be desirable to adjust or change the camcontour, usually this cannot be done; or, only at prohibitive expense.An example of the need for such a cam is found in the art of rotarysprinklers; that is, it is often desirable to arrange a sprinkler tocover other than a circular area. Fixed cams are used to control theangular position of a nozzle or to move a deflector into the path of thestream to produce, for example, an essentially square spray pattern.Often the area to be covered is irregular and sufficiently unique thatit would be impractical and much too expensive to predeterrnine the camshape capable of producing the desired irregular spray pattern. Also, asthe plants grow, changes in the spray pattern may be required.

SUMMARY OF THE INVENTION This invention is directed to an adjustable camand adjusting means therefore and is summarized in the followingobjects:

First, to provide an adjustable cam wherein a series of relativelynarrow strips are disposed in mutually contacting relation and form attheir corresponding ends a series of narrow cam elements, the stripsbeing relatively movable longitudinally so that the cam elements may bemoved to define collectively a variable cam surface.

Second, to provide an adjustable cam, as indicated in the precedingobject, which may be injection molded in one piece at a nominal costwith the cam strips disposed in radial relation and joined at theirradially inner ends by yieldable connecting loops, the strips beingmovable from their molded positions into mutually contacting linearrelation or circular relation.

Third, to provide an adjustable cam, as indicated in the precedingobjects, wherein each strip includes a laterally directed portionforming opposing cam elements.

Fourth, to provide an adjustable cam and adjusting means thereforewherein the adjusting means also includes cam rollers and includes amanually engageable handle for manipulating the rollers to change thecam contour.

Fifth, to provide an adjustable cam and adjusting means therefore whichis particularly adapted for use in conjunction with a rotary sprinklerwhereby the pattern may be varied to distribute the water in variouspredetermined irregular patterns.

Sixth, to provide a sprinkler, as indicated in the preceding object,which incorporates a valve whereby the volume of water output may bevaried by adjustment of the pattern control cam.

DESCRIPTION OF THE DRAWINGS FIG. I is an enlarged fragmentary view ofthe cam structure, shown in the form in which it is injection molded.

FIG. 2 is a sectional view, taken through 2-2 of FIG. 5, showing one ofthe cam strips.

FIG. 3 is a fragmentary top view, at a reduced scale, showing the camstructure in its operating condition.

FIG. 4 is a fragmentary bottom view thereof.

FIG. 5 is an enlarged fragmentary view, taken from 5-5 of FIG. 3,showing the outer side of the cam structure as assemblied for operation.

FIG. 6 is a fragmentary side view, showing a modified form of the camstructure, as it appears upon being injection molded.

FIG. 7 is a fragmentary side view, showing the modified cam assembledfor operation.

FIG. 8 is a sectional view, taken through 8-8 of FIG. 7.

FIG. 9 is a fragmentary plan view of the modified cam.

FIG. I is a longitudinal sectional view of a rotary sprinkler whichutilizes the cam structure, the sprinkler being shown in the positionfor maximum water trajectory.

FIG. I1 is a similar longitudinal sectional view, but showing the partsarranged for minimum water trajectory.

FIG. 12 is a transverse sectional view, taken through I2- 12 of FIG. 10.

FIG. 13 is a fragmentary longitudinal sectional view, taken through13-13 of FIG. I0.

Reference is first directed to the cam structure shown in FIGS. 1through 5. The cam structure 1 is injection molded as a single piece andincludes a plurality of cam strips 2, which in their initial or moldedposition extend radially from a common center. The radially inner endsof the cam strips are joined by connecting loops 3. The walls of theloops are substantially thinner than the thickness of the cam strips andthe width of the connecting loops are substantially less than the widthof the cam strips. As a consequence, the cam strips can be manipulatedfrom the initial condition shown in FIG. I to a condition in which thecam strips are formed into a cylinder with their major dimensionextending axially. The sides of each cam strip taper so that when thecam strips are arranged to form a cylinder, their sides are in mutualcontact. When in their cylindrical condition, as indicated in FIGS. 3and 4, the connecting loops permit limited relative longitudinalmovement of the cam strips.

In order to hold the cam strips in their cylindrical condition, each camstrip is provided with a cross channel 4. Collectively, the crosschannels form an annular groove which receives a retaining band 5 ofelastomeric material.

At its axial end, opposite from the connecting loop 3, each cam strip isprovided with a lateral extension 6 from its edge opposite from thecross channel 4. The lateral extension forms at its upper edge an upperor axially outer cam element 7, and at its lower edge, a lower oraxially inner cam element 8. The cam elements 7 continue across theupper ends of the cam strips.

The radially inner edges of the cam strips are provided with rudimentaryserrations 9 so that when the cam strips are pressed radially inwardagainst a cylindrical member by the constricting force of the retainingband 5, the cam strips tend to be held frictionally in place. However,they may be forced axially with respect to each other a limiteddistance. That is, the cam elements 7 and 8 form annular cam trackswhich may be varied in contour by applying axial force upward ordownward until the desired cam track contour is attained, as will bedescribed in more detail hereinafter.

Reference is now directed to FIGS. 6 through 9, which i] lustrate a camstructure 10, which differs from the cam structure 1 only in that itscam strips 2 are not tapered and are initially cast in parallelrelation, as indicated in FIG. 6, so that they may be pressed together,as indicated in FIG. 7, to fonn a lineal as distinguished from acircular cam. In this case, the cam strips are held by clamping bars 11and spring loaded clamping pins or fasteners 12, as shown in FIG. 9.

Of the many applications for an adjustable cam structure, particularlyof the cylindrical type, a rotating sprinkler offers a prime example.The application of the adjustable cam structure is therefore illustratedin conjunction with the sprinkler, shown in FIGS. 10 through 13.

The sprinkler here illustrated includes an outer housing 13, having abase portion 14 and an outer cylindrical sleeve 15. Mounted within theouter housing 13 is an inner or motor housing 16 which is cylindricaland includes a flange 17 for attachment to the periphery of the baseportion I4 of the housing 13 by means of screws 18.

The inner and outer housings define a cylindrical cam receiving cavity19. The cavity 19 receives the cam strips 2 and their connecting loops 3with the extensions 6 extending radially inward over the upper end ofthe motor housing 16.

Clamped between the flanged lower end of the motor housing I6 and thebase portion 14, by its periphery, is a swirl plate 20. Formed below theswirl plate in the base portion 14 is an inlet cavity 21 connected to aninlet passage 22. Formed above the swirl plate 20 is a motor cavity 23.The peripheral portion of the swirl plate 20 is provided with helicallydirected swirl slots 24.

The upper end of the motor cavity 23 is closed by a wall 25, having abearing 26 therein. A corresponding bearing 27 is provided in the swirlplate 20. Joumaled by the bearings 26 and 27 is a tubular rotor stem 28.

Within the motor cavity, the rotor stem is provided with a thrust flange29. Thrust washers 30 are provided between the flange 29 and the wall25.

The rotor stem 28 is provided with triangular impact lobes 31 and isprovided with one or more side ports 32. Surrounding the impact lobes 31is a drive ring 33 having four sides.

The motor construction thus far described is not, per se, part of thepresent invention and is merely shown and described to illustrate ameans of accomplishing rotation. A motor of this type is disclosed inUS. Pat. No. 3,3l5,898, issued Apr. 25, I967.

The upper end of the rotor stem 28 receives a nozzle 34, which includesa vertical portion 35 and an angularly directed portion 36. Extendingupwardly from the vertical portion 35 is a guide boss 37, having a smallbore which receives a rod 38 extending downwardly through the rotor stem28 and provided at its lower end with a valve head 39, which cooperateswith a valve seat 40 provided at the lower end of the rotor stem 28. Aspring 41 urges the rod 38 upwardly and the valve head 39 away from itsvalve seat 40. In actual operation, the valve head does not closeagainst the valve seat 40.

The vertical portion 35 of the nozzle is provided with diametricallydisposed lower pivot lugs 42 which pivotally support a first pivot frame43. The frame 43 includes a radially directed yoke 44 on which ismounted an inner cam follower wheel 45 for engagement with the lower orinner cam elements 8.

The frame 43 also includes an upwardly directed yoke 46 which overliesthe upper end of the rod 38 and is provided with a cam 47, adapted tocause axial movement of the rod on pivotal movement of the frame 43. Ahandle 48 extends from the pivot frame 43.

The vertical portion 35 of the nozzle is also provided with an upper setof diametrically disposed pivot lugs 49 which pivot a second pivot frame50. The frame 50 includes a radial portion 51, having an outer camfollower wheel 52 which engages the upper or axially outer cam elements7.

The second pivot frame 50 also includes a deflector tongue 53 whichextends over the angularly directed portion 36 of the nozzle to a pointbeyond the discharge end of the nozzle. The tongue 53 is provided with aclearance slot 54 for the rod 38. The second pivot frame 50 is providedwith a spring cup 55 which receives a spring 56 for yieldable engagementwith the upwardly directed yoke 46 of the first pivot frame 43 so thatthe cam follower wheels are urged towards each other.

The cam structure and the rotary sprinkler cooperate as follows:

Before the sprinkler is operated, it is rotated manually and the handle48 is manipulated to cause the cam followers to engage the cam elements7 and 8. In the region surrounding the sprinkler, where it is expectedthat maximum water trajectory will be needed, that portion of the camtrack is depressed, as indicated in FIG. 10. In the region where it isexpected that minimal water will be required, the handle is tilted sothat the cam followers raise the corresponding portion of the cam track,as indicated in FIG. 11.

Then, with the sprinkler in operation, the handle 48 is manipulated tocause the trajectory of the water stream to increase or decreaseaccording to the particular spray pattern desired. Control of the wateris not limited merely to its trajectory, but as the trajectory isreduced, the volume of water is reduced by reason of adjustment of thevalve formed by the valve head 39 and valve seat 40. If the trajectoryis short, the area to be covered is less and therefore less water isrequired. As a consequence, uniform water distribution is attained eventhough the area to be irrigated is irregular.

In order to have suflicient friction, the radially inner sides of thecam strips 2 are provided with serrations 2a, indicated partially inFIGS. 1 and 2.

hile particular embodiments of this invention have been shown anddescribed, it is not intended to limit the same to the details of theconstructions set forth, but instead, the invention embraces suchchanges, modifications and equivalents of the various parts and theirrelationships as come within the purview of the appended claims.

1 claim:

1. An adjustable cam comprising:

a. a plurality of cam strips;

b. at least one cam element formed on each cam strip and facinglongitudinally with respect to the strip;

c. and a plurality of loops integrally connecting the strips to permitdisposition of the strips and the cam elements in side-by-side contact,said loops permitting limited longitudinal displacement of the strips toeffect corresponding relatively displacement of the cam elements;

d. said cam elements defining collectively a cam track of variablecontour.

2. An adjustable earn, as defined in claim 1, wherein:

a. the cam strips define a cylinder, the connecting loops are located atone axial end of the cylinder, and the cam elements extend radially toform a circular cam track.

3. An adjustable cam, as defined in claim 1, wherein:

a. the strips are disposed in parallel relation and the cam elementsform a linear cam track.

4. An adjustable cam, as defined in claim I, wherein:

a. each cam strip is provided with a lateral extension and the axiallyfacing edges thereof have opposing cam elements.

5. An adjustable cam, as defined in claim 2, wherein:

a. each cam strip is provided with a radial extension and the axiallyfacing edges thereof have opposed cam elements defining a pair of camtracks.

6. An adjustable earn, as defined in claim 1 wherein:

a. the cam strips are initially disposed in radial relation with the camelements extending axially and the connecting loops at the radiallyinner ends of the strips;

b. the loops being relatively narrow to permit the strips to be turnedfrom a radial direction to an axial direction, and whereby the camelements are disposed in a radial direction.

7. An adjustable cam comprising:

a. a plurality of cam strips of wedge shaped crossflsection andarranged, when placed side-by-side, to form longitudinally directedsegments of a cylinder, the cam strips being relatively slidable axiallywith respect to the cylinder;

b. a pair of axially directed opposed cam elements carried by each camstrip, the cam elements forming collectively a pair of opposed circularcam traclts;

c. and means for yieldably retaining the cam strips in side by-sidecontact, said means permitting relative axial displacement of the camstrips to effect change in the contour of the cam tracks.

I I. i I 8

1. An adjustable cam comprising: a. a plurality of cam strips; b. atleast one cam element formed on each cam strip and facing longitudinallywith respect to the strip; c. and a plurality of loops integrallyconnecting the strips to permit disposition of the strips and the camelements in sideby-side contact, said loops permitting limitedlongitudinal displacement of the strips to effect correspondingrelatively displacement of the cam elements; d. said cam elementsdefining collectively a cam track of variable contour.
 2. An adjustablecam, as defined in claim 1, wherein: a. the cam strips define acylinder, the connecting loops are located at one axial end of thecylinder, and the cam elements extend radially to form a circular camtrack.
 3. An adjustable cam, as defined in claim 1, wherein: a. thestrips are disposed in parallel relation and the cam elements form alinear cam track.
 4. An adjustable cam, as defined in claim 1, wherein:a. each cam strip is provided with a lateral extension and the axiallyfacing edges thereof have opposing cam elements.
 5. An adjustable cam,as defined in claim 2, wherein: a. each cam strip is provided with aradial extension and the axially facing edges thereof have opposed camelements defining a pair of cam tracks.
 6. An adjustable cam, as definedin claim 1, wherein: a. the cam strips are initially disposed in radialrelation with the cam elements extending axially and the connectingloops at the radially inner ends of the strips; b. the loops beingrelatively narrow to permit the strips to be turned from a radialdirection to an axial direction, and whereby the cam elements aredisposed in a radial direction.
 7. An adjustable cam comprising: a. aplurality of cam strips of wedge shaped cross-section and arranged, whenplaced side-by-side, to form longitudinally directed segments of acylinder, the cam strips being relatively slidable axially with respectto the cylinder; b. a pair of axially directed opposed cam elementscarried by each cam strip, the cam elements forming collectively a pairof opposed circular cam tracks; c. and meanS for yieldably retaining thecam strips in side-by-side contact, said means permitting relative axialdisplacement of the cam strips to effect change in the contour of thecam tracks.